FIELD OF THE INVENTION
The present invention relates to a method for dyeing keratinous fibers using indole compounds, to the compositions themselves, and to devices for implementation thereof.
The compounds of the indole family, in particular, 5,6-dihydroxyindole and its derivatives, are well known for their use in the dyeing of keratinous fibers and, in particular, of human hair.
The Applicant has discovered that it was possible, with certain indole compounds defined below, to obtain varied shades with glints or natural shades from light to deep blond and warm shades, such as coppery or deep auburn shades, using these indole compounds in a neutral or acid medium. The application of this composition being followed by the application of an alkaline oxidizing composition.
The Applicant has also discovered that by using these specific indole compounds in the method defined above, it was possible to obtain dyes which had good resistance to light and to chemical treatments, such as permanent waving.
The colorings obtained by virtue of the use of these specific indole compounds, within the framework of the method according to the invention, also have the advantage of being uniform, even after several super-positions. They also cover well.
The invention therefore relates to a new dyeing method using certain specific indole derivatives in a cosmetically acceptable medium, at a neutral or acid pH, the application of these derivatives under the indicated pH conditions being followed by the application of an alkaline oxidizing solution.
The invention also relates to the compositions used within the framework of this method.
Further subjects of the invention will become apparent on reading the description and the examples which follow.
The method according to the invention is essentially characterized in that a tinctorial composition containing, in an aqueous cosmetically acceptable medium having a pH of less than or equal to 7, at least one indole derivative corresponding to the formula: ##STR2##
in which:
R.sub.1 denotes hydrogen, alkyl or COOH; PA1 R.sub.2 denotes hydrogen or alkyl; PA1 R denotes hydrogen a Si(CH.sub.3).sub.3, or COalkyl group; and PA1 X denotes hydrogen, OH, or OSi(CH.sub.3).sub.3 ; it being possible for X in the 4- or 5-position also to denote O-alkyl, on condition PA1 that when X is in the 5-position and OR denotes OH in the 4- or 6-position, only one of the groups R.sub.1 and R.sub.2 then differs from hydrogen; PA1 that when X represents hydrogen, OR is in the 7-position and R.sub.2 is hydrogen; PA1 that when R denotes hydrogen and X denotes OH, OR and X are, respectively, in the 5- and the 6-position and R.sub.1 denotes COOH, PA1 and the corresponding acid salts, PA1 is applied in a first step and in that, after a dwell time followed by rinsing and rubbing dry, an alkaline oxidizing solution is applied in a second step, this application being followed by rinsing and shampooing.
It should be noted that the present process does not involve the use of iodide ions. Such ions are not included within the initial composition of the first step, nor are they mixed with this composition. The iodide ions also are not included in the alkaline oxidizing solution of the second step.
The Applicant has found that this method enabled varied shades with glints or natural shades from light to deep blond and of copper and deep auburn to be obtained which were uniform after several superpositions and covered the hair well.
In the formula (I), alkyl preferably denotes a radical having 1 to 4 carbon atoms.
The following may be mentioned among the compounds of formula (I) which can be used in this method according to the invention: 7-hydroxy-2,3-dimethyl-4-methoxyindole, 7-hydroxyindole, 5-acetoxy-6-hydroxyindole, 6-hydroxy-2-methyl-5-methoxyindole, 2-carboxy-5,6-dihydroxyindole, 5,6-di(trimethylsilyloxy)indole and 2-methyl-4-hydroxy-5-ethoxyindole.
The compounds particularly preferred are 7-hydroxy-2,3-dimethyl-4-methoxyindole, 7-hydroxyindole, 5-acetoxy-6-hydroxyindole and 2-methyl-4-hydroxy-5-ethoxyindole.
According to a preferred embodiment, these compounds may be used as a mixture with other compounds such as 5,6-dihyroxyindole, 2-methyl-5,6-dihydroxyindole or 6-hydroxyindole and its corresponding acid addition salt.
The indole compound of formula (I) used according to the invention is preferably present in the composition applied in the first step in proportions of between 0.02 and 5% and, in particular, from 0.05 to 3% by weight relative to the total weight of the composition.
The aqueous medium appropriate for dyeing consists of water and preferably a water-solvent(s) mixture, the solvent(s) being chosen from organic solvents such as ethyl alcohol, propyl or isopropyl alcohol, tert-butyl alcohol, ethylene glycol, ethylene glycol monomethyl, monoethyl or monobutyl ethers, propylene glycol, propylene glycol and dipropylene glycol monomethyl ethers and methyl lactate.
The preferred solvents are ethyl alcohol and ethylene glycol monobutyl ether.
The solvent(s) is(are) present in the water/solvent(s) medium in concentrations of between 0.5 and 75% by weight relative to the total weight of the composition and, in particular, between 2 and 50% and preferably between 2 and 20% by weight.
This medium may also contain surface-active agents, which are preferably nonionic, and thickeners well known in the prior art in the field of hair dyeing, such as guar gum, xanthan gum and cellulose polymers, in proportions of between 0 and 3%.
The pH may be adjusted using alkalinizing or acidifying agents customarily used in hair cosmetics.
The composition may also contain adjuvants customarily used in cosmetics, such as perfumes or preservatives.
With a view to varying the shade of the colors obtained with the indole derivatives of formula (I), it is possible to add to the tinctorial composition direct dyes and/or precursors of oxidation dyes and/or couplers and/or rapid oxidation dyes which are well known in the field of hair dyeing, such as, for example, in the publication "HARRY'S COSMETICOLOGY" 7th Edition, edited by J. B. WILKINSON and R. J. MOORE, pages 521 to 545.
The oxidizing composition preferably consists of an aqueous solution of oxidizing agent which is mixed at the time of use with an alkaline aqueous solution which may contain solvents and surface-active agents of the type defined above.
The oxidizing agent is preferably chosen from hydrogen peroxide, urea peroxide and persalts, such as alkali metal or ammonium percarbonates and perborates.
The alkaline agents are chosen from ammonia, alkanolamines such as 2-amino-2-methylpropan-1-ol, monoethanolamine, monomethylethanolamine or dimethylethanolamine.
The aqueous oxidizing agent solution may contain solvents of the type defined above, surface-active agents and also auto-emulsifiable waxes or polyoxyethylenated alcohols to thicken the solutions.
The proportion of oxidizing agent in the composition applied in the second step is between 1 and 15% by weight relative to the total weight of the oxidizing composition, and preferably between 1 and 8% by weight.
The proportion of oxidizing agent in the alkaline oxidizing composition which is applied to the hair is between 1 and 10% by weight relative to the total weight of the composition, and preferably between 1 and 5%.
The pH of the oxidizing composition is between 8.5 and 12.
The invention also relates to a two-component agent for dyeing hair.
The first component (A) consists of a composition containing, in a cosmetically acceptable medium, a compound of formula (I) as defined above and at a pH of less than or equal to 7; the second component (B) consists of an alkaline aqueous solution of an oxidizing agent as defined above.
This dye agent may be packaged in a multi-compartment device or dyeing kit containing, in separate compartments, the components (A) and (B).
Again, it must be noted that iodide ions are not included in component (A) nor are they mixed therewith. Component (B) also does not contain iodide ions.
The following examples are intended to illustrate the invention without, however, having a limiting character.